Deck-lig-ht



' UNITED STATES PATENT OFFICE.

HENRY LANERGAN, 0F EAST CAMBRIDGE, MASSACI-IISETTS.

DECK-LIGHT.

Specification of Letters Patent No. 81,247, dated January 29, 1861.

To all whom it 'may concern:

Be it known that I, HENRY LANERGAN, of East Cambridge, in the county of Middlesex and State of Massachusetts, have invented a new and useful or Improved Glass Light for the Deck or other Part of a Navigable Vessel, and do hereby declare the same to be fully described in the following specification and illustrated in the accompanying drawings, of which Figure 1 is a top view; Fig. 2, a side elevation; Fig. 3, a bottom view, and Fig. 4, a transverse and central section of it.

The ordinary glass deck light consists, generally speaking of an elongated block of glass. IVhen inserted in the deck of a vessel it has been held in place by cement or by means ofl a frame of metal screwed to the deck and arranged so as to lap over the edges of the deck light. Breakage of a deck light is a very common occurrence on shipboard, and besides when the deck light is fixed in place by means of putty or cement, the latter is likely to become either loosened or cracked. The consequence of either breakage of the decklight or loosening of its cement is leakage of water through the deck whenever it is Washed. Furthermore, the fixation of a deck light into the deck by means of putty or a metallic frame or both is a matter of much trouble and care.

In making my invention I have endeavored to produce a decklight which may be used as a side light and be easily fixed in a deck or other part of a vessel without requiring putty or a metallic frame to hold it in place and when once fixed in place will not be likely to be broken or to cause leakage of water through the deck or part in which it may be inserted.

In the several figures of the drawings exhibiting my said new deck light it is represented as cylindrical in its upper portion a, immediately below which is a screw of the same diameter as the part a. The part 0,'

immediately below the screw is convex in form or may be hemispherical, and terminates in a polygonal projection CZ, for the reception of a wrench to be used for rotating the decklight while being screwed into a or fixed within a deck. The convex part c, .is to project below the deck and to serve as a dispenser of the light which may be received into the glass parts a, The object of the cylindrical part a, which generally speaking should be about one half an inch in depth, is to prevent breakage or injury to the thread of the screw b. Tere the screw to be continued upward to the upper surface of t-he part a, its thread would be likely to get broken more or less at the edge of the said top surface by such articles as are usually thrown on or allowed to fall upon the deck light. Furthermore, the part a, serves as a shoulder or stop for the screw and to make a tight joint when the decklight is screwed into the deck. It is intended that the thickness of the parts a, Z), shall be equal or about equal to that of the planking of the deck.

Instead of making the light dispensing part c, with a polygonal projection (l, it may be constructed with one or more recesses for the reception of a wrench; but there is an objection to such, as they break up or impair the diusion of the light. The polygonal projection operates to diffuse light not only downward, but in all directions horizontally, and therefore it performs important functions not incident to such recess or recesses. By making the bottom of the part Z more or less convex the diffusion of light will be more general than when such bottom is fiator a plane.

The deck light formed as described is to be cast in one piece of glass by means of a mold.

Preparatory to inserting the deck light into a deck, a cylindrical hole having a diameter equal to that of the cylinder on which the screw is developed should be bored in the deck. Next, this hole should be enlarged in its upper part so as to be capable of receiving` and closely fitting to the estopping part a. Next, by means of a suitable auger or tool a. female screw suitable to receive and.corresponding with the screw should be cut in the remainder of the hole. Afterward, the decklight may be screwed into the hole and set tightly down therein by means of a wrench applied to the part (Z. Should shrinkage of the deck at the junction of the shoulder and the screw take place at any time so as to affect the tightness of the joint a very slight rotation of the decklight will suffice to so compress the upper part of the screw thread as to render the joint water tight. `1

The form of the decklight is such as to make it much more capable of withstanding blows or shocks without breaking than the oblong decklights in general use.

The improved manufacture of glass deck light as constructed With the several parts a, b, c, d, thereof arranged together substantially in the manner and so as to operate together and for the purpose as specified.

HENRY LANERGAN.

Witnesses:

ARTHUR NEILL, F. P. HALE, J R. 

